Field
This invention relates to surgical cannulas, and more particularly, to a surgical cannula for introducing multiple minimally invasive surgical instruments through a single opening in the body.
Background
Minimally invasive surgery (MIS) (e.g., endoscopy, laparoscopy, thoracoscopy, cystoscopy, and the like) allows a patient to be operated upon through small incisions by using a camera and elongated surgical instruments introduced to an internal surgical site. The surgical site often comprises a body cavity, such as the patient's abdomen. The body cavity may optionally be distended using a clear fluid such as an insufflation gas. In traditional minimally invasive surgery, the surgeon manipulates the tissues by using hand-actuated end effectors of the elongated surgical instruments while viewing the surgical site on a video monitor.
One or more cannulas may be passed through small (generally 1 inch or less) incisions or a natural body orifice to provide entry ports for the minimally invasive (e.g., endoscopic, laparoscopic, and the like) surgical instruments, including a camera instrument (e.g., endoscope, laparoscope, and the like). A surgeon is able to perform surgery by manipulating the surgical instruments externally to the surgical site under the view provided by the camera instrument.
It is typical to provide several cannulas for a minimally invasive surgical procedure. Generally each cannula will provide access to the surgical site for a single surgical or camera instrument. For example, four cannulas may be provided with one cannula being used to introduce a camera instrument and the remaining three cannulas being used to introduce surgical instruments. While the small incisions necessary for placing a cannula are less traumatic than the incision necessary for open surgery, each incision still represents a trauma to the patient.
In an effort to reduce the trauma of minimally invasive surgery even further, techniques are being developed to allow minimally invasive surgery using only a single cannula. This may be accomplished by using a somewhat larger cannula that can accommodate all of the instruments required for the surgery. Minimally invasive surgery performed through a single cannula may be referred to as single port access (SPA) surgery. The single cannula may be introduced through a body orifice and be referred to as Natural Orifice Transdermal Endoscopic Surgery (NOTES). Single port surgery may also be referred to as bellybutton surgery when the navel (umbilicus) is used as the location for the single cannula.
If multiple surgical instruments and/or camera instruments are to be introduced to a surgical site through a single cannula, it can become difficult manage the instruments within the cannula. It is desirable to use as small a cannula as possible consistent with the size of the instruments to be passed through the cannula. This may make it difficult to introduce the additional instruments and to maintain the necessary mobility of the instruments.
These difficulties may be even greater for robotically controlled minimally invasive surgical procedures because of the robotic controllers on the instruments. The robotic controllers may limit the visibility and accessibility of the cannula. The robotic controllers may render the instruments less agile with regard to introduction into the cannula.
In view of the above, it would be desirable to provide an improved cannula for carrying out minimally invasive surgical procedures that facilitates the introduction of multiple surgical instruments and/or camera instruments to a surgical site through a single compact cannula.